“Energetic” compounds are used extensively in a wide variety of applications, e.g., in rocket propellants, explosive formulations, and the inflation of automobile and aircraft occupant restraint bags. It is generally preferred that such compounds have a high energy content yet be relatively insensitive to impact, so that accidents are avoided and energy is released only when intended. The requirements of insensitivity and high energy are in conflict, making the development of new energetic compounds a difficult and challenging synthetic problem.
Previously known energetic compounds can possess one or more disadvantages, e.g., they are overly impact-sensitive, difficult to synthesize on a large scale, or not sufficiently energetic. Typically, energetic compounds used to inflate occupant restraint bags in automobiles or aircraft contain potentially toxic heavy metal initiating materials, e.g., lead styphnate.
The present invention provides a class of compounds, i.e., azidoaminotriazole, various salts and complexes of nitrosoguanazine, and azidonitramines, that may have potential as propellants, explosives and initiating materials, including laser initiated materials, and that do not contain toxic heavy metals.
In addition, it is anticipated that nitrosoguanazine compounds and their metal salts may undergo denitrosation in the body, releasing nitric oxide. The nitrosoguanazine compounds and their metal salts may accordingly be used as biomedical and pharmaceutical agents, i.e., as so-called “NO-donors.” NO donors are useful as vasodilating agents, insofar as NO activates guanylyl cyclase, increasing intracellular levels of cyclic guanosine 3′,5′-monophosphate (cGMP), and CGMP brings about smooth muscle relaxation. Previously known NO donors include, for example, nitroglycerin (glyceryl trinitrate), isosorbide dinitrate, isosorbide-5-mononitrate, erythrityl tetranitrate, pentaerythritol tetranitrate, sodium nitroprusside, S-nitroso-N-acetylpenacillamine (SNAP), linsidomine chlorohydrate (also known as SIN-1), and the so-called “NONOates,” complexes of nitric oxide and nucleophiles that contain the N2O2-group and release NO upon heating or hydrolysis without need for activation. The biomedical and pharmaceutical application of many known NO donors is limited, however, as a result of unwanted side effects, an undesirable NO release profile, or the like. Thus, there is a continuing need in the art for novel biomedical and pharmaceutical agents useful as vasodilators.
Russian workers refer to azidoaminotriazole in two articles, but do not provide a method of making or any properties of this material: (1) Kofman, T. P., Kartseva, G. Yu., Namestnikov, V. I., and Paketina, E. A., Russ. J. Org. Chem. 1998, 34 (7), 1032 (translated from Zh. Org. Khim., 1998, 34 (7), 1084); and (2) Kofman, T. P., Russ. J. Org. Chem. 2001, 37 (8), 1158 (translated from Zh. Org. Khim., 2001, 37 (8), 1217). Currently, there is no known preparation for azidoaminotriazole in the literature.
The conversion of amines to diazonium salts via primary nitrosoamines is known. However, because primary nitrosoamines so readily convert to diazonium salts, it is quite difficult to isolate these primary nitrosoamine materials. Consequently, primary nitrosoamines have been very limited in their availability for other uses. Reports of isolation of primary nitrosoamines in the literature are rare. One report by H. Gehlen and J. post, Liebigs in Ann. Chem., Bd. 665 (1963), pages 144-149, describes the preparation of 3-nitrosamino-4-aryl-5-alkyl-1,2,4-triazoles. However, their starting materials, 3-amino-4-aryl-5-alkyl-1,2,4-triazoles, contain only one reactive amine. The starting material of the present invention, guanazine (3,4,5-triamino-1,2,4-triazole), on the other hand, may contain three reactive amines and may allow the selective preparation of a primary nitrosoamine in the presence of other reactive amines in the same molecule.